JPS60216599A - Method of producing thickn film hic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for manufacturing a thick film HIC, and in particular to multilayering of a thick film HIC. (Prior Art) In conventional thick film HIC circuit printing, The circuit parts (conductors, resistors, etc.) to be used have a thickness of 20 to 40 μm, and in the case of multilayering, an insulating layer is layered on top of this, and then circuits are printed and stacked.

FIG. 1 shows the process of conventional multilayer printing. After printing a conductor 20 on a ceramic substrate 1 shown in FIG. 1(a) (FIG. 1(b)), an insulating layer 30 is printed. After that, the conductor 21 is further stacked and printed on it (Fig. 1 (d)), and an insulating layer is overlaid on it (Fig. 1 (C)). Multilayer HICs were manufactured using a process of stacking layers.

However, with this method, there is a step difference in the thickness of the printed film, so when stacked, the circuit breaks at the edge of the step, as shown in Figure 2, or the circuit becomes extremely thin, resulting in disconnection failures. (P), "turn show" (Q) occurs, which has the disadvantage of deteriorating reliability.

(Object of the Invention) The object of the present invention is to eliminate the level difference that occurs when printing thick film HIC, and to eliminate the 7z disconnection that tends to occur conventionally.

The objective is to eliminate short circuits and improve yield and reliability.

(Structure of the Invention) The present invention is a method for manufacturing a thick film HIC in which wiring circuits are stacked in multiple layers, and in which a door protrusion caused by the thickness of a conductor, a resistor, etc. in a layer having a conductor pattern, etc. is embedded and insulated. This method of manufacturing a thick film HIC is characterized by sequentially forming upper layers after planarization.

(Example) Fig. 3 is an explanatory diagram showing the manufacturing method of the present invention, where 1 is a ceramic substrate, 2o is a first conductor, 2 is a second conductor, 4
0 is an insulating layer before firing, 40ae41m is an insulating layer after firing, and 50.51 is an intermediate insulating layer.

First, the first conductor 2o is printed on the ceramic substrate 1 (
Figure 3(b)). Next, a buried insulating layer 40 is formed to have the same thickness as the first conductor 2o by printing in the recessed portion (dented portion) in the peripheral area between the first conductors 20 (FIG. 3(C)). The buried insulating layer 4o is made of a thick film that can have fluidity at around 80° C. and can be easily bonded to the first conductor 2o and flattened. This thick film is made by dispersing and kneading glass frit into a vehicle in which resin is dissolved in an organic solvent. By firing in the state shown in Fig. 3(,), the buried insulating layer 4o is formed as shown in Fig. 3(,).
The space between the first conductors 20 is filled and flattened like the insulating layer 40a after firing shown in FIG. The buried insulating layer 40 is generally formed by printing, and the printed pattern is formed on the first conductor 2.
Make it a negative 9 turn with a pattern of 0, and 3
Printed A' turns spaced ~5 μm apart are preferred. This distance is between the first conductor 20 and the buried insulating layer 40 in FIG. 3(c).
This is the interval between This minute gap is filled by melting during firing, and no difference in height occurs at the joint with the first conductor 20. Moreover, as a result, the accuracy error of the master turn of the mask can be tolerated.

Next, an intermediate insulating layer 56 (of low fluidity) is formed by printing (FIG. 3(e)). The firing temperature at this time is 800℃
It is necessary to keep the temperature below 20 to 50°C. Subsequently, as shown in FIG. 3(f)K, the second conductor 21 is printed, and thereafter, the buried insulating layer 41a and the intermediate insulating layer 5 are sequentially printed in the same manner. In this case, the firing temperature increases by 2% for each layer as you go to the upper layer.
It is necessary to choose a paste material that is 0-50°C lower.

Further, when forming the buried insulating layer and the intermediate insulating layer using an insulating paste, in addition to printing as described above, spin coating or wheeler coating can also be used. This method involves placing a substrate with paste on a rotating body and applying yeast using centrifugal force.
The film thickness is controlled by adjusting the viscosity and solid content of the insulating paste to appropriate conditions.

(Effects of the Invention) In the thick film HIC manufacturing method according to the present invention, in addition to the conventional single insulating layer, a buried layer is provided to flatten the circuit printing surface of each layer, so the circuit printing is performed by overlapping the upper layer. In this process, there is no step difference in many overlapping parts of the circuit pattern, and the occurrence of disconnection of one-thick film HIC.
This has the advantage of eliminating short circuits and improving reliability.

Also, since a flat surface can be obtained, fine 4-turn printing is possible.

It has the advantage that fine wires can be easily printed and circuit wiring with high packaging density is possible.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the process of conventional multilayer printing;
FIG. 2 is an explanatory diagram illustrating that reliability is lowered due to wire breakage and short-circuiting in the prior art, and FIG. 3 is an explanatory diagram illustrating the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Ceramic substrate, 20... First conductor, 21.
..., ``Second conductor, 40... Insulating layer before firing, 40m, 41a
... Insulating layer after firing, 50.51 ... Intermediate insulating layer. Patent applicant Oki Electric Industry Co., Ltd. Figure 1 Figure 2 20 ~ 1 (0) Roni = = 22 = Top 1 0

Claims (1)

[Claims] A method for manufacturing a thick film HIC in which wiring circuits are stacked in multiple layers, in which unevenness caused by the thickness of conductors, resistors, etc. in a layer having 4' turns of conductors, etc. is flattened with a buried insulating layer, and then A method for manufacturing a thick film HIC, characterized in that upper layers are sequentially formed.